This type of film is designed for use in instant cameras meaning the photos are developed instantly or as fast as possible. Instant film packs contain the proper chemicals needed for developing the photos. The camera initiates the developing process right after a picture is taken.
In most instant cameras, the film is pulled through rollers which break a pod open that contains chemicals. The assorted chemicals then spread out over the film's surface and a few minutes later the photographed image is produced from the camera on a hard copy.
Time delays are built into the chemicals so each layer of the film can be developed in the proper sequence. Instant film is available in 24mm x 36mm size which is similar to 135 film and up to 8 x 10 inches in size. However, there is a small border surrounding the photo. It also comes in assorted speeds.
Early versions of instant film came on rolls, but now it usually comes on film packs of 8-10 exposures. Some film packs have a battery to drive motors in the camera. Instant film is ideal when it's necessary to quickly view the image. It's good for law enforcement, health care, scientific studies and personal identification, such as passports.
Film costs about $1 an exposure on average.
